An interdisciplinary approach to the study of brain-endocrine interactions, our research program employs methodologies of radioimmunoassay, electrophysiology, neuropharmacology and neuroanatomy. Our long-term goals are to understand the mechanisms by which the brain controls endocrine secretion and is, in turn influenced by the secreted hormones. How are rhinencephalic-hypothalamic circuits involved in reproduction and sex behavior, or in lactation and maternal behavior? With a deep interest in the brain-pituitary-gonad axis in reproduction and lactation, sites and mechanisms of production, transport and action of synaptic transmitters, neuronal peptides, pituitary protein hormones and gonadal and adrenal steroids are under intensive investigation. Feedback actions of releasing factors, pituitary tropins and target organ hormones on endocrine secretion and behavior are also of primary concern. Rhythmic neuroendocrine phenomena of various periodicities are being studied with coordinated methodologies in search of "Zeitgebers" and their mode of transmission. Physiological and anatomical relations of l lower brain stem, hippocampus and amygdala with the basal hypothalamus are being explored by stereotaxic surgery, electrical stimulation-recording techniques and the antidromic identification of neurons. Preoptic neurons antidromically identified as projecting to the basal hypothalamus-median eminence will be subjected to electrical and chemical stimuli including the iontophoresis of various transmitters. Endocrine, neuropharmacological and immunological methods of controlling fertility will continue to be explored.